CD4+ T cells facilitate the RT-induced abscopal effect by promoting antigen cross-presentation to CD8+ T cells at unirradiated tumor sites

Background <p>The local effect of radiotherapy (RT) is enhanced by CD8⁺ T-cell responses elicited through dendritic cell (DC)-mediated cross-presentation of tumor antigens, facilitated by RT-induced damage-associated molecular patterns. The abscopal effect&mdash;regression of non-irradiated tumors&mdash;has been observed clinically, particularly in combination with immune checkpoint blockade, although it remains uncommon. To better understand how to enhance this effect, we investigated two RT/&alpha;-programmed…